Moved the Cornerstone viewport code to an extension. Tons of changes to rollup and package.json files to make everything play nicely

Packages-react/extensions/ohif-cornerstone-extension/.editorconfig

@@ -0,0 +1,9 @@
+root = true
+
+[*]
+charset = utf-8
+indent_style = space
+indent_size = 2
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true